The new EPA regulation provides a critical step in addressing PFAS contamination in drinking water. Reducing PFAS in drinking water offers a range of potential health benefits, both for individuals and the population as a whole, including lower cancer risk, improved immune function, reduced risk of birth complications, lower cholesterol levels and developmental advantages in children.
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The 1980 Groundwater Management Act includes provisions to help prevent this scenario. Under the Act, there are two kinds of areas in which groundwater is regulated:
1. Irrigation Non-Expansion Areas (INAs) – wells larger than small residential wells are metered, and their groundwater use is reported annually. In addition, there is a prohibition on new irrigated agriculture (defined as two or more acres).
2. Active Management Areas (AMAs) – metering and reporting of groundwater use; prohibition on new irrigated agriculture; developments of six or more homes cannot be platted without proof of a 100-year supply of water that is physically, financially, and legally available. Every ten years, ADWR develops a new management plan for each AMA, with increasingly rigorous conservation and efficiency requirements for all sectors. Agriculture tends to be the biggest water-using sector, and since 1980, new irrigated agriculture has been prohibited within the AMAs and Irrigation Non-Expansion Areas. (No such prohibition is in place outside the AMAs and INAs, which is why some parts of the state have seen an influx of industrial-scale, groundwater-dependent agriculture.) Farms with grandfathered wells are permitted to pump groundwater to irrigate their crops. Energy costs to pump groundwater are a consideration for farmers, particularly as the water table falls and more energy is required to pump it for use. At some point, the energy costs may render some types of irrigated agriculture unprofitable.
Usually, if municipal water is available it is much less expensive and far more reliable than water from an individual private well. Outside AMAs and INAs, there is virtually no regulation on the amount of water a well owner can pump.
Central Arizona municipal water providers will continue to adapt to ensure sufficient and resilient water supplies. Past successes include significant reductions in the use of water per capita through conservation, the extensive use of reclaimed water, the development of diverse water portfolios that include Colorado River water and local Salt and Verde River watersheds, the banking of Colorado River and reclaimed water underground in local aquifers and collaborative regional planning that includes leases and exchanges of both water and infrastructure.
Additional adaptations may include enhanced conservation, land-use planning that includes incentivizing development on lands with better access to renewable surface water supplies, new and innovative regional partnerships to exchange and lease water and leverage infrastructure between municipal water providers, new infrastructure to treat and deliver wastewater as drinking water, increasing the capacities of local reservoirs, transferring high-priority Colorado River water into Central Arizona via purchase or lease and importation of new water supplies such as desalinated ocean water or brackish groundwater.
Outside of Central Arizona, groundwater, surface water, brackish groundwater desalination, and ocean desalination projects are being implemented. These include the Yuma Desalting Plant, the North Central Arizona Pipeline, and the Binational Desalination Plant located in the Sea of Cortez. Learn more.
Surface water is water found on the surface of the earth. Arizona gets its surface water primarily from the Colorado River and the local Salt and Verde River watersheds, though there are surface waters found in rivers, creeks, and lakes throughout the state.
Groundwater is water found under the surface of the earth between the pores and fractures of sand, gravel, and rock known as aquifers. We have access to a large groundwater resource and a large aquifer under the Phoenix region, and there are groundwater basins across the state of Arizona. Groundwater needs to be carefully managed because it is largely non-renewable on a human-time scale. Surface water from rivers is renewed by rain and snow, unlike groundwater, which is withdrawn much faster than it is replenished in Arizona. It can take decades, hundreds, or even thousands of years to replenish to the level that we have now. It's important to carefully manage it and look out over 100 years to ensure that groundwater is sustainable over that period. To explore changes in groundwater levels throughout Arizona, use the Arizona Water Blueprint tool created by the Kyl Center for Water Policy, one of the pillars of the Arizona Water Innovation Initiative.
Arizona has been at the forefront of sustainable and resilient water management for more than 100 years. The state’s Assured Water Supply program, a result of the 1980 Groundwater Management Act, requires that municipalities within Active Management Areas ensure 100 years of water supply for new development. However, outside of AMAs and INAs, there is still inconsistent regulation on groundwater pumping.
In our 100-year timeframe, we are looking out over multiple generations to ensure that we have that sustainable, secure supply. We've already seen innovations in the way that we conserve, manage, and reuse water, and have grown our diverse water portfolio.
Colorado River
Climate change is impacting the surface water flows in the Colorado River Basin due to higher temperatures and dryer soil. Research tells us that for roughly every degree Celsius increase from climate change, we see about a 10% decline in the river flow on the Colorado River. As we look forward we need to factor those changes into our calculations and we need to adapt our water demand to be more efficient, and we need new policies.
The cost of water will very likely increase. Your water bill comes from your local water utility. Most water utility costs are related to infrastructure — water mains, pumps, tanks, treatment plants, and meters, for example — but the cost of wholesale water supplies is also significant. Colorado River water is delivered on a wholesale basis to some, but not all, water utilities in Central Arizona. The cost of these deliveries is passed on to customers. The cost of wholesale Colorado River water delivered through the Central Arizona Project will increase due to shortages.
Different water utilities depend on wholesale supplies from the Central Arizona Project to varying degrees. Those that are more dependent will experience cost increases that are relatively higher. Many water utilities have access to alternative supplies — groundwater, reclaimed water, and Salt and Verde River water, for example — but alternative supplies and the infrastructure necessary to deliver them may be more expensive, and increased costs will be passed on to customers. Costs for water for replenishment will likely rise, either directly through a rate increase or indirectly through property taxes.
Colorado River shortages may impact tap water deliveries for “direct use” municipal water providers. For “indirect use” municipal water providers, shortages will impact the aquifers by reducing the amount of recharge. In Central Arizona, less than 350,000 acre-feet per year of Colorado River water is used directly at surface water treatment plants. This compares with total Colorado River water deliveries in Central Arizona during non-shortage years of more than 1,600,000 acre-feet annually. Fundamentally, this means that Central Arizona can withstand some Colorado River shortages without impact on tap water deliveries. The impact of shortages will also fall on aquifers because there will be less Colorado River water available for recharge and replenishment and more finite groundwater will be pumped.
Several reservoir and water management decisional documents and agreements that govern the operation of Colorado River facilities and management of the Colorado River are scheduled to expire at the end of 2026. These include the 2007 Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead (2007 Interim Guidelines), the 2019 Drought Contingency Plans, as well as international agreements between the United States and Mexico pursuant to the United States-Mexico Treaty on Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande (1944 Water Treaty).
The Bureau of Reclamation announced its intent to prepare an Environmental Impact Statement for post-2026 operations and solicited public comments on the scope of specific operational guidelines, strategies, and any other related issues that should be considered in the upcoming Environmental Impact Statement. This input was used to develop the proposed federal action, which allows for developing robust operating guidelines for Lake Powell and Lake Mead without precluding upstream or downstream activities needed to protect critical reservoir elevations at Lake Powell and Lake Mead. The action also is intended to allow for the development of innovative and flexible operating guidelines that provide improved predictability of water availability and enhanced opportunities for conservation.
The Colorado River is over-allocated, meaning that the total volume of water users are entitled to on paper each year nearly always exceeds the physical amount of water the system produces. Over two decades of drought have compounded this problem, and many experts believe that climate change will cause long-term reductions in the Colorado River’s flows.
According to the U.S. Geological Survey, every temperature increase of 1 degree Celsius (1.8 degrees Fahrenheit) in the Upper Basin results in a 9.3% reduction in flows. Learn more.
Colorado River water imported into Central Arizona via the Central Arizona Project (CAP) canal is used by municipal water providers in five main ways:
- It can be delivered to a surface water treatment plant, where it is treated to meet Safe Drinking Water Act requirements and then pumped through the municipal water provider’s transmission and distribution system to customers’ taps
- It can be delivered directly to a non-potable use such as a park or golf course
- It can be delivered to another entity in exchange for other water sources
- It can be delivered to an underground storage facility (USF) for percolation into local aquifers, or
- It can be delivered to a groundwater savings facility (GSF) where it is used to grow crops.
Municipal uses are modest, encompassing only 13% of our total Colorado River Basin water use.
Outside of municipal uses, Colorado River water is used for irrigated agriculture (59%), reservoir evaporation (12%), and riparian and wetlands (16%).
Water Security
Focus on reducing outdoor water use, such as what we use to water grass yards and maintain pools, because it accounts for as much as 70% of municipal water use. In contrast, over 90% of water used indoors is treated and recycled in Arizona.
Municipal demand comprises less than 40% of total water demand in Central Arizona, and Colorado River water makes up only about 40% of that demand. Groundwater, Salt River Project water, and reclaimed water make up the rest. Long-term reductions in outdoor water use by urban users are helpful because they enable water providers to stretch available supplies to serve more people and businesses. While helpful, especially at a local level, reductions in municipal water use won’t necessarily translate into water left in Lake Mead: Junior priority users are entitled and eager to use water that more senior contract holders leave in the system. Learn more.
Experts are most concerned about parts of the state that are largely reliant on a single resource like the Colorado River, which is currently experiencing a megadrought, or only groundwater. We should be paying the most attention to the strategies we need to manage risk in those areas. Marginalized populations in high-income countries are the communities that most often experience water insecurity. In the U.S., this includes low-income families, migrant workers, minority-headed households, houseless people, and tribal populations. For example, across the Navajo Nation, lack of access to potable water is common, and that access is hindered by water infrastructure costs, which can be as much as 70 times higher for a Navajo family relying on hauled water than for non-Indigenous families with piped delivery.
Arizona Water for All uses community-participatory research approaches to address water insecurity. We offer communities a pathway to solicit research that centers their water needs—and access to data that communicate those water needs to decision-makers. We recognize that climate change and infrastructural decline make it difficult to bring piped water to everyone who needs it. For these reasons, we do not pursue “one-size-fits-all” solutions. Instead, we work alongside communities to co-develop programs and technologies that address their unique water needs.
For example, community-based participatory research (CBPR) is a collaborative process between community members, community-based organizations, and academics. Arizona Water for All seeks to build long-term relationships with community members impacted by water insecurity to better understand their situations and create programs and technologies that directly address their interests and concerns. CBPR has the potential to make research more responsive to existing needs and to enhance a community’s ability to address important health issues.
Water insecurity is a lack of safe, reliable, sufficient, and affordable water for a thriving life. Being water insecure involves inadequate or inequitable access to water for drinking or basic sanitation. A common misunderstanding is that human water insecurity mainly comes from living in droughts, deserts, overexploited aquifers, or other conditions of physical water scarcity. But that’s incorrect. Most water insecurity is created by humans: through the institutions we create to govern and distribute water, laws that determine who owns water, and the price of water. These are the main determinants of who can reliably access it for drinking and sanitation—and it’s why we find human water insecurity even in places where water is physically abundant.
Water security is defined as the ability to access and benefit from affordable, adequate, reliable, and safe water for general well-being and a healthy life.
Water Quality
The new EPA regulation provides a critical step in addressing PFAS contamination in drinking water. Reducing PFAS in drinking water offers a range of potential health benefits, both for individuals and the population as a whole, including lower cancer risk, improved immune function, reduced risk of birth complications, lower cholesterol levels and developmental advantages in children.
While this rule only targets a specific set of PFAS compounds, it represents significant progress in protecting public health. The EPA estimates the new PFAS regulation will yield significant public health benefits over time, including the prevention of thousands of deaths and reduced instances of serious illness.
In short, yes. Readily available water filtration systems can remove most PFAS from home drinking water that has not already been municipally treated.
Carbon block filters, RO and some ion exchange resin systems that are certified to remove PFAS will carry a “NSF/ANSI 53” or “NSF/ANSI 58” label. RO systems are considered the most effective at removing a variety of contaminants, including PFAS. Some types of activated carbon filters, particularly those designed specifically for PFAS removal, can be effective.
It is critical that once in use, these systems also be maintained with new, regularly scheduled filter changes. The EPA offers more information on what to look for in home systems.
The effectiveness of different methods for removing PFAS at home can vary depending on the specific type of PFAS and the level of contamination in your water. No single home filtration method is guaranteed to completely eliminate PFAS.
If you're concerned about PFAS in your drinking water, it's also recommended that you have your water tested by a certified laboratory. This can help you determine the level of PFAS contamination and choose the most appropriate treatment option.
Regardless of the treatment method used, the process of PFAS removal generates a concentrated waste stream containing PFAS. Traditional wastewater treatment processes, like those focused on removing bacteria and organic matter, are largely ineffective at eliminating PFAS.
Several technologies show promise for PFAS removal in wastewater, but they are still under development. For example, similar to municipal water treatment, advanced GAC or ion exchange resins specifically designed for PFAS capture are being explored.
In addition, high-pressure membrane filtration systems like nanofiltration or RO can be effective, but they can be expensive and generate significant PFAS-laden solid or liquid brine wastes. High-temperature incineration can destroy PFAS compounds, but this method raises concerns about air pollution and significant energy inputs.
Treating PFAS in wastewater is an ongoing challenge that requires ongoing research and development of new technologies.
Municipal water providers are currently addressing PFAS contamination in their water supplies. There isn't a one-size-fits-all solution, but several treatment technologies can be effective, depending on the type and level of PFAS present.
For example, adsorption is a method that uses a special media, like granular activated carbon (GAC) or ion exchange resins, to capture PFAS molecules and remove PFAS from drinking water. GAC is a highly porous material that provides a large surface area for PFAS to cling to. Ion exchange resins work by attracting and exchanging charged ions, including some PFAS types.
The effectiveness of adsorption depends on several factors, including the specific PFAS, the capacity of the media and other co-occurring chemicals in water. PFAS accumulated on the GAC or ion exchange materials must be properly disposed of, or thermally regenerated.
Membrane filtration utilizes high-pressure membranes, like nanofiltration or reverse osmosis (RO), to physically separate PFAS from water. RO membranes are very tight and effectively remove most contaminants, including a wide range of PFAS. Membrane filtration is generally more expensive to implement and maintain compared to adsorption, and PFAS still occurs in concentrated brine waste streams that must be properly disposed of.
The selection of a treatment method for PFAS removal by a municipal water provider involves several considerations. For example, it’s important to balance the cost of implementing and maintaining a treatment system. In addition, some treatment methods, like RO, may remove beneficial minerals along with contaminants and might necessitate adding minerals back into the treated water.
Public water systems across the country have until 2027 to begin monitoring regulated PFAS compounds. This allows them time to plan and budget for potential treatment upgrades if needed. If a water system exceeds the standards, they will have an additional time to implement solutions to bring their PFAS levels down.
There is currently more than $1 billion available through the federal Inflation Reduction Act to treat PFAS.
The Arizona Department of Environmental Quality (ADEQ) has confirmed the presence of PFAS in public water systems across the state based on a screening program proactively developed in 2018. The agency is currently working to update their data in light of the new federal regulation, which will apply to approximately 950 water systems in the state.
It's important to note that most of Arizona's public water systems serve fewer than 3,300 people and the EPA's current testing requirements only apply to larger systems. However, in 2022, ADEQ and the Water Infrastructure Finance Authority of Arizona agreed to dedicate a portion of federal Safe Drinking Water Act funds to ensure every public water system in the state is tested for PFAS.
PFAS are known for their unique properties that make them valuable in a variety of products. For example, PFAS repel water, oil and stains, making them ideal for coatings on nonstick cookware, rain gear and carpets. Their ability to withstand high temperatures is useful in fire-resistant materials, fire fighting foams at airports and electrical insulation. Although several types of PFAS have been phased out, many are still widely used.
PFAS contamination can come from a variety of sources, including manufacturing facilities that use PFAS in their products, municipal wastewater treatment plants, landfills and waste sites where improper disposal can lead to contamination of surrounding soil and water and sewage sludge treated with PFAS-containing materials.
The widespread use and persistence of PFAS have led to their presence in drinking water supplies across the country. PFAS can build up in the bodies of animals and humans, known as bioaccumulation, when ingested through contaminated water or food.
Tap water is the water that is delivered to customers who are connected to the main supply of a local water system. Tap water is treated before delivery to meet the requirements of the Safe Drinking Water Act and is delivered within proper pressure parameters. Tap water is delivered to households, businesses, and industries and is used for many different purposes, including domestic uses indoors, domestic uses outdoors (such as landscape irrigation), and business and industrial purposes of all kinds, both indoor and outdoor. In a general sense, tap water is drinking water, though it can be used for non-drinking water purposes such as landscape irrigation or industrial processing.
Climate Change
Drought is a prolonged period of below-average precipitation severe enough to negatively impact the environment and human activities. Drought is a natural occurrence and Arizona is especially sensitive to drought, since water is scarce here even during average years. Population growth continues to increase demand for water. Drought can impact domestic water supplies, ranching and farming production, vegetation, forest health and wildlife populations.
Arizona has been in some stage of drought since 1994, according to statewide precipitation patterns. Water resources in Arizona are diverse and can arrive from hundreds of miles away; such is the case with the Colorado River water. Water in the Colorado River are generated by snowmelt runoff from mountain ranges that can be located in as far as Colorado and Wyoming states, upper in the Colorado River Basin. Even water supplies that are generated within the state can originate much further than the place of consumption- either located deep underground (in the form of groundwater) or generated by snowmelt from mountains located tens of miles away from Central Arizona, where most of the state's residents live and work. Learn more.
While climate change is affecting the entire state, the impacts are felt differently depending on where and who you are. Experts are most concerned about parts of the state that are largely reliant on a single resource like the Colorado River, which is currently experiencing a megadrought, or only groundwater. We should be paying the most attention to the strategies we need to manage risk in those areas. Marginalized populations experiencing water insecurity emphasized by climate change include low-income families, migrant workers, minority-headed households, houseless people, and tribal populations.
For example, across the Navajo Nation, lack of access to potable water is common, and that access is hindered by water infrastructure costs, which can be as much as 70 times higher for a Navajo family relying on hauled water than for non-Indigenous families with piped delivery, according to the report.
The state of Arizona is working on a Priority Climate Action Plan, led by the Governor’s Office of Resiliency. Simultaneously, two climate plans are being developed by Maricopa and Pima counties. Cities including Phoenix, Tucson and Flagstaff are also working on plans. There is need to advance water augmentation opportunities, water purification, and different cooperative agreements between cities and agricultural users, other states, and with tribal communities to be able to increase the available supply from the Colorado River.
ASU is supporting the City of Phoenix and regional partners as they develop a new advanced water purification treatment plant that will allow the recycling of municipal wastewater to drinking water quality standards, and deliver that water directly back to residents. This will generate tens of millions of gallons of new water every day reduce our reliance on drought-affected rivers like the Colorado River and allow us to be more efficient and reuse and recycle our water multiple times.
Climate change is impacting the surface water flows in the Colorado River Basin due to higher temperatures and dryer soil. Research tells us that for roughly every degree Celsius increase from climate change, we see about a 10% decline in the river flow on the Colorado River. As we look forward we need to factor those changes into our calculations and we need to adapt our water demand to be more efficient, and we need new policies.
Climate change is threatening water resources in the Southwest through increased temperatures, drought, and more erratic precipitation. Effective adaptation will require flexible decision-making and the incorporation of technological innovation with Indigenous and local knowledges.
The EPA claims annual precipitation has decreased in Arizona during the last century, and it may continue to decrease. Soils are likely to be drier, and periods without rain are likely to become longer, making droughts more severe.
The decline in snowpack could further limit the supply of water for some purposes. Much of Arizona’s water supply is groundwater, which should be relatively less impacted than surface water supplies, though less Colorado River water will mean more groundwater pumping and less aquifer replenishment. The Salt-Verde system does not appear to be as susceptible to climate change impacts as the Colorado River system. Learn more.
Water Supply
Arizona’s population has grown steadily over the years, however through significant investments in water conservation and infrastructure and the reuse of water, our water use is essentially the same as it was more than half a century ago.
To take a closer look at this pattern, replacing agricultural lands with municipal development almost always results in a net decrease in water use. It takes approximately 6 acre-feet per acre to grow cotton or alfalfa in our desert climate, and only around 1 acre-foot per acre to serve a subdivision, though these numbers can vary depending on climate, the crop grown, and the density of the urban development. In addition, almost all of the water that enters urban wastewater treatment systems can be reclaimed and reused.
Future sources of water include: desalinated, brackish groundwater; desalinated ocean water (noting that currently desalination of ocean water may be part of Arizona’s water supply in the future, but it is very expensive and energy-intensive); direct potable reuse of reclaimed water; transfers of Colorado River water from agricultural to urban uses; limited inter-basin transfers of groundwater.
In the Greater Phoenix area, we have access to several sustainable sources of supply. We have surface water from the Colorado River and our local Salt and Verde River Watershed, we have groundwater, and we have recycled and reused water.
Based on 2019 data, 72% of the water used in Arizona is for agriculture, while 22% is used for cities (municipal use) and 6% is used for industries. This is in line with how water is used in much of the world. Learn more.
Arizona has four main sources of water: Colorado River water, in-state surface water (like the Salt River & Verde River managed by SRP), groundwater (water pumped from aquifers) and reclaimed water. Learn more.
In short, yes. Readily available water filtration systems can remove most PFAS from home drinking water that has not already been municipally treated.
Carbon block filters, RO and some ion exchange resin systems that are certified to remove PFAS will carry a “NSF/ANSI 53” or “NSF/ANSI 58” label. RO systems are considered the most effective at removing a variety of contaminants, including PFAS. Some types of activated carbon filters, particularly those designed specifically for PFAS removal, can be effective.
Regardless of the treatment method used, the process of PFAS removal generates a concentrated waste stream containing PFAS. Traditional wastewater treatment processes, like those focused on removing bacteria and organic matter, are largely ineffective at eliminating PFAS.
Several technologies show promise for PFAS removal in wastewater, but they are still under development. For example, similar to municipal water treatment, advanced GAC or ion exchange resins specifically designed for PFAS capture are being explored.
Municipal water providers are currently addressing PFAS contamination in their water supplies. There isn't a one-size-fits-all solution, but several treatment technologies can be effective, depending on the type and level of PFAS present.
The Arizona Department of Environmental Quality (ADEQ) has confirmed the presence of PFAS in public water systems across the state based on a screening program proactively developed in 2018. The agency is currently working to update their data in light of the new federal regulation, which will apply to approximately 950 water systems in the state.
PFAS are known for their unique properties that make them valuable in a variety of products. For example, PFAS repel water, oil and stains, making them ideal for coatings on nonstick cookware, rain gear and carpets. Their ability to withstand high temperatures is useful in fire-resistant materials, fire fighting foams at airports and electrical insulation. Although several types of PFAS have been phased out, many are still widely used.
Arizona’s population has grown steadily over the years, however through significant investments in water conservation and infrastructure and the reuse of water, our water use is essentially the same as it was more than half a century ago.
Future sources of water include: desalinated, brackish groundwater; desalinated ocean water (noting that currently desalination of ocean water may be part of Arizona’s water supply in the future, but it is very expensive and energy-intensive); direct potable reuse of reclaimed water; transfers of Colorado River water from agricultural to urban uses; limited inter-basin transfers of groundwater.
In the Greater Phoenix area, we have access to several sustainable sources of supply. We have surface water from the Colorado River and our local Salt and Verde River Watershed, we have groundwater, and we have recycled and reused water.
Based on 2019 data, 72% of the water used in Arizona is for agriculture, while 22% is used for cities (municipal use) and 6% is used for industries. This is in line with how water is used in much of the world. Learn more.